Browsing by Author "Ristow, Peter Gustav"

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    GlobalFiler® express DNA amplification kit in South Africa: Extracting the past from the present
    (Elsevier, 2016) Ristow, Peter Gustav; Cloete, Kevin Wesley; D’Amato, Maria Eugenia
    In this study, the GlobalFiler1 Express amplification kit was evaluated for forensic use in 541 South African individuals belonging to the Afrikaaner, amaXhosa,1 amaZulu,1 Asian Indian and Coloured population groups. Allelic frequencies, genetic diversity parameters and forensic informative metrics were calculated for each population. A total of 301 alleles were observed ranging between 5 and 44.2 repeat units, 43 were rarely observed partial repeats and seven were novel. The combined match probability (CMP) ranged from 2.21 10 26 (Coloured) to 5.21 10 25 (AmaZulu), and the combined power of exclusion (CPE) 0.9999999978 (Afrikaaner) to 0.99999999979 (AmaZulu) respectively. No significant departures from Hardy-Weinberg equilibrium (HWE) were observed after Bonferroni correction. Strong evidence of genetic structure was detected using the coancestry coefficient u, Analysis of Molecular Variance (AMOVA) and an unsupervised Bayesian clustering method (STRUCTURE). The efficiency of assignment of individuals to population groups was evaluated by applying likelihood ratios with WHICHRUN, and the individual ancestral membership probabilities inferred by STRUCTURE. Likelihood ratios performed the best in the assignment of individuals to population groups. Signs of positive selection were detected for TH01 and D13S317 and purifying/balancing selection for locus SE33. These three loci also displayed the largest informativeness for assignment (In) values.
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    Novel buffer for long-term preservation of DNA in biological material at room temperature
    (Taylor and Francis Ltd., 2024) Kasu, Mohaimin; Ristow, Peter Gustav; Burrows, Adria Michelle
    The collection and preservation of biological material before DNA analysis is critical for inter alia biomedical research, medical diagnostics, forensics and biodiversity conservation. In this study, we evaluate an in-house formulated buffer called the Forensic DNA Laboratory-buffer (FDL-buffer) for preservation of biological material for long term at room temperature. Human saliva stored in the buffer for 8 years, human blood stored for 3 years and delicate animal tissues from the jellyfish Pelagia noctiluca comb jelly Beroe sp., stored for 4 and 6 years respectively consistently produced high-quality DNA. FDL-buffer exhibited compatibility with standard organic, salting out and spin-column extraction methods, making it versatile and applicable to a wide range of applications, including automation